For those of you who want to find your way round catalogues or try to identify a rose variety, a certain amount of knowledge of the anatomical terms is desirable.
Many of these are in the language of the botanist to ensure commonality.
Starting from the ground up, we have: -
Root system. Most of the roses we buy these days are on a rootstock or understock. The root system is fibrous i.e. full of fibres, and relies on these to uptake water and food for conversion to sap to feed the plant.
Bud. An embryonic shoot that may eventually produce either foliage or flowers. The bud is located in the axil of the leaf stalk.
Bud Union. The location where the scion (Bud) was affixed to the rootstock. This should be well calloused by the time the plant is sold by the grower. The bud is inserted into the cambium layer of the rootstock. The cambium layer is the green layer between the outer bark and the inner hardwood of the stem or cane.
Canes. The stem of a rose, either the main stem, which is often called the trunk, or lateral stems or branches. Canes can be a very important part in identifying a variety of rose. Canes can be thick and rigid; pliable; straight; crooked; hairy; scaly; red, green, purple, brown, or grey.
Thorns. A thorn is actually a branch of the plant that becomes hard and pointed. Cactus and lemons have thorns. Roses have prickles, as they are not a fundamental part of the stem. Thorns, as we will continue to call them, can often serve to identify a plant. Some are straight, others are hooked, some are hooked towards the main cane, others are hooked away from the main cane; some grow in pairs, others are scattered; some are white, others red or brown. There may be bristles between them, they may be on the back of the leaves, and some varieties have no thorns at all.
Foliage. There is a wide variation in rose foliage. The leaves are characteristically pinnate – that is, composed of more than three leaflets arranged in two rows along a common stalk. The shape may be broad in the base and narrow at the top, or the complete reverse. The surface of the leaflet may be wrinkled as in the rugosas, or smooth. The edges can be scalloped, pointed, turned under or blunt at the tip. Leaflets may have thorns on the undersides of the leaflets and along the stalks, or have no thorns at all. Each of these factors varies from variety to variety and class to class and is used by the experts to help identify a particular variety.
Where the leaf stalk attaches to the cane are the stipules. Their shape and the way they are attached to the leaf stalk vary from species to species. They may be toothed, fringed, comb-like or slashed.
Enough for today. Some time in the future we will talk about the rest of the plant – leading up to the flower head.
